As Corion explained, what you've asked for can't be done since the set of possible characters in UTF8 is much bigger than the set of possible characters in Latin-1.

HTML does allow you to represent any character regardless of the encoding. For example, the character 'Ā' is not in Latin-1 but you can include it in HTML with &#256;. However that would only work if you stored HTML encoded text in your database - which would be an odd thing to do.

By far the best answer is to update your database and web pages to UTF8.